Apoderus coryli (L.) – a Biologically Little Known Species of the Attelabidae (Coleoptera)

Abstract

Hazel-leaf roller weevil (Apoderus coryli /L./) is a noteworthy species from the perspective of biology and forestry; it belongs to the family Attelabidae. Its occurrence, development and harmfulness were studied in surroundings of Brno city in 2011 and 2012. Imagoes of the first generation and those of not very numerous second generation are observed to winter in the area under study. From the beginning of May to the end of July they occur on the host woody plants (mainly on Carpinus betulus and Corylus avellana). The males and females consume on average 21 and 33 cm2 of leaves, respectively. The fertilized females cut into the leaf blade in an original manner, and bite into the main and side leaf veins. They fold the withering part of the blade lengthwise to the adaxial face first, and then forming the folded blade into a short cylindrical roll. In the initial phase of rolling, the females lay up on average 1.0 egg into the leaf rolls on C. betulus (1.2 on C. avellana). In total, they make around 30 rolls. The larvae emerge on average within 10 days. In the course of 3 to 4 weeks, they pass through two instars only and damage on average 4 cm2 of leaves. This work describes the occurrence and development of the beetles of the first and second generation. It provides an assessment of the mortality of the individual development stages of A. coryli within the rolls. It was demonstrated that rolling of the leaves causes on average 9 times more damage to the trees than maturation feeding of the beetles.

Keywords

• <i>Apoderus coryli</i>
• Attelabidae
• occurrence
• maturation feeding
• leaf rolls
• reproduction